Eukaryotes originated from the symbiosis of an Asgard archaeon, the alphaproteobacterial ancestor of mitochondria, and possibly additional bacterial contributions.
Molecular hydrogen (H2) is a widespread, energetically efficient reductant supporting microbial metabolism across most known ecosystems. Although seafloor hydrothermal vents are major energy providers for H2-oxidizing microorganisms, the diversity of […]
In the deep-sea environment of the East Pacific Rise, where sunlight does not penetrate and the surroundings are known for their extreme temperatures, skull-crushing pressures, and toxic compounds, lives Riftia […]
![An unrooted maximum-likelihood phylogenetic tree of the catalytic subunit (HydA) of [FeFe] hydrogenases and the hybrid hydrogenases. The tree was constructed based on 3,677 amino acid sequences using the LG + C20 + R + F model. The numbers at the branches indicate the aLRT (approximate likelihood ratio test) and ultrafast bootstrap (within bracket) support values, each with 1,000 replicates. The scale bar corresponds to the expected number of substitutions per site. Colored circles at the tip indicate sequences from eukaryotes and major archaeal groups. All other sequences are from bacteria. -- Cell](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/06/How-Archaea-The-Third.png?resize=1200%2C720&ssl=1)
An international scientific team has redefined our understanding of archaea, a microbial ancestor to humans from two billion years ago, by showing how they use hydrogen gas.
